As climate change accelerates, extreme heat is fast emerging as a silent public health emergency, exposing deep inequalities in how people live, work and access care. For thousands living in informal settlements and heat-trapping homes, the crisis is no longer looming; it is already unfolding.
Cape Town’s recent heatwave has been described by health experts as an early warning of a far more dangerous future, where rising temperatures place mounting pressure on already strained public healthcare systems.
Speaking at the opening of the Partnership for Healthy Cities 2026 Summit in Rio de Janeiro, Brazil, on Tuesday, global health leaders warned that intensifying heatwaves are placing growing strain on health infrastructure, frontline workers and vulnerable populations.
The event, coordinated by Bloomberg Philanthropies in partnership with the City of Rio de Janeiro, has brought together more than 340 participants from 70 cities worldwide to share solutions to prevent non-communicable diseases, with climate-linked health risks rapidly climbing the agenda.
In March, the South African Weather Service confirmed that several areas across the Namakwa District and the Western Cape shattered long-standing temperature records. Preliminary data shows multiple weather stations recorded their highest March temperatures in more than a decade, a stark indicator of a warming trend that is accelerating.
Extreme weather events are becoming more frequent and severe across sub-Saharan Africa, with South Africa experiencing repeated episodes of climate volatility. But beyond the headline temperatures lies a quieter crisis: the growing burden on public health systems.
A study published in the National Library of Medicine titled Identifying heat thresholds for South Africa towards the development of a heat-health warning system, found that exposure to heatwaves is directly linked to adverse health outcomes.
While South Africa currently relies on fixed temperature thresholds for heat alerts, researchers warn that more sophisticated heat health warning systems are needed, systems that can better predict real-world health impacts and guide timely interventions.
On the sidelines of the summit, public health specialist and epidemiologist Natacha Berkowitz told the Sunday Times that the true impact of extreme heat is often under-recognised in primary healthcare, but no less dangerous.
“From a city health perspective, we provide primary healthcare and don’t necessarily see emergency cases directly,” she said.
Addressing heat requires a holistic, intersectoral approach, not just a health systems response.
— Public health specialist Natacha Berkowitz
“However, we are prepared for any issues that may arise from exposure to high heat. Our facilities are geared to support vulnerable populations, particularly the elderly, as well as children and young people.”
She noted that Cape Town has prioritised training clinicians to identify and manage heat-related illnesses, a critical step as cases of dehydration, heat exhaustion and complications from chronic conditions rise during extreme weather.
But Berkowitz stressed that healthcare systems cannot respond in isolation.
“Addressing heat requires a holistic, intersectoral approach, not just a health systems response,” she said. “The city’s climate change strategy includes both mitigation and adaptation measures, with different departments working together to reduce community-level impacts.”
This includes strengthening facility readiness, improving resource planning, expanding staff training and adapting service delivery during periods of extreme heat, all essential in preventing facilities from becoming overwhelmed.
Health experts at the summit emphasised that protecting vulnerable populations must be at the centre of any response, warning that preventable deaths linked to heat exposure remain an urgent and unacceptable reality.
The challenge is global.
In Accra, a situational analysis conducted through the Partnership for Healthy Cities revealed rising urban heat exposure, particularly in low-income and densely populated communities. The findings point to escalating health risks, low levels of public awareness, and significant gaps in healthcare readiness and urban infrastructure.
We are seeing rising temperatures around the world, and heat is an extreme public health issue.
— Kelly Larson, injury prevention lead at Bloomberg Philanthropies
Recommendations emerging from the analysis include integrating heat stress into municipal policy, implementing heat-health action plans and early warning systems, and improving coordination across sectors. These measures are expected to inform the city’s broader resilience strategy, including a proposed bylaw mandating green infrastructure to reduce heat-related illness and deaths.
Kelly Larson, injury prevention lead at Bloomberg Philanthropies, said extreme heat is now firmly on the global health agenda.
“We are seeing rising temperatures around the world, and heat is an extreme public health issue,” she said. “That is why we have included it as one of the key intervention areas for the Partnership for Healthy Cities.”
She added that cities within the network are increasingly committing to heat-focused interventions, supported by shared learning and technical expertise.
“We are working with cities to develop and share policies that protect the most vulnerable, because they are the ones most affected,” Larson said.
As cities like Cape Town confront intensifying and prolonged heatwaves, the message from global health leaders is unequivocal, climate change is no longer just an environmental concern, it is a public health crisis unfolding in real time, with the greatest risks borne by those least equipped to cope.
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